WaterAid today responded to a pledge by International Development Secretary Justine Greening to more than double DFID investment to support developing countries' economies, warning this should not replace spending in critical water and sanitation programmes. Ms Greening made the announcement at a keynote speech at the London Stock Exchange on Monday, pledging to increase DFID spending on economic development to £1.8 billion in 2015/16. "Justine Greening is right to identify economic growth as an engine of poverty reduction. We are pleased to see this focus on fragile and post-conflict states, to help them move out of extreme poverty towards a healthier, more productive state," said Henry Northover, global head of policy at WaterAid. "But we cannot achieve broad-based economic growth in societies where a large proportion is burdened by a lack of access to clean water and sanitation. They are the backbone of girls' access to education, better health, and lifting a society out of poverty. "We would also like to see clarity on the impact this funding will have on other aid spending." By a 2012 World Health Organisation estimate, a lack of safe water and sanitation costs the countries of sub-Saharan Africa the equivalent of 4.3 per cent of their GDP each year. Based on World Bank figures, that is in excess of $55 billion in 2012 alone – or more than the amount pledged in aid commitments to sub-Saharan African countries that year, based on OECD reporting. Access to safe drinking water and improved sanitation results in a healthier workforce, reducing time lost to diarrhoeal illnesses and associated health care costs, and increases productivity. It also allows children to stay in school and get a better education, improving their future prospects. Sustainable solutions for improved water and sanitation require long-term investment. The World Bank's MIGA Conflict-Affected and Fragile Economies Facility (CAFEF) provides political risk insurance to foreign investors. DFID has promised £20 million to the first loss layer, a welcome contribution toward encouraging investors. However, WaterAid has cautioned the UK government against taking a narrow approach in supporting UK businesses in the delivery of aid programmes. "The UK has been a world leader in keeping its aid agenda independent to ensure it is supporting truly local, sustainable development," Mr Northover said. "We know that tying aid to a donor's national or corporate interests simply does not work as well. We need to draw in local systems, entrepreneurs and production capacity to achieve a sustainable end to aid dependency."